Can you use your private key to restore your wallet on another platform? For example if I have a private key from Samurai Wallet and I try to restore it on Wasabi Wallet would this work?

247Bitcoin

In addition to the question in the title if private keys are not cross platform, what would happen if Samurai Wallet was to disappear? Would you loose all of your coins if you got another phone? Does this also apply to cold storage as well?